ParsedDocumentEntry's fields are made final and added some guards to prevent null inputs.

LarsKrogJensen · bbakerman · commit bc388c48972b · 2017-07-01T11:44:56.000+10:00
Added unit test for ParsedDocumentEntry as well.
diff --git a/src/main/java/graphql/execution/preparsed/PreparsedDocumentEntry.java b/src/main/java/graphql/execution/preparsed/PreparsedDocumentEntry.java
@@ -5,25 +5,30 @@
 
 import java.util.Collections;
 import java.util.List;
+import java.util.Objects;
 
 /**
  * An instance of a preparsed doucument entry represents the result of a query parse and validation, like
  * an either implementation it contains either the correct result in th document property or the errors.
  */
 public class PreparsedDocumentEntry {
-    private Document document;
-    private List<? extends GraphQLError> errors;
+    private final Document document;
+    private final List<? extends GraphQLError> errors;
 
     public PreparsedDocumentEntry(Document document) {
+        Objects.requireNonNull(document);
         this.document = document;
+        this.errors = null;
     }
 
     public PreparsedDocumentEntry(List<? extends GraphQLError> errors) {
+        Objects.requireNonNull(errors);
+        this.document = null;
         this.errors = errors;
     }
 
     public PreparsedDocumentEntry(GraphQLError error) {
-        this.errors = Collections.singletonList(error);
+        this(Collections.singletonList(Objects.requireNonNull(error)));
     }
 
     public Document getDocument() {
@@ -33,8 +38,7 @@ public Document getDocument() {
     public List<? extends GraphQLError> getErrors() {
         return errors;
     }
-
-
+    
     public boolean hasErrors() {
         return errors != null && !errors.isEmpty();
     }
diff --git a/src/test/groovy/graphql/execution/preparsed/PreparsedDocumentEntryTest.groovy b/src/test/groovy/graphql/execution/preparsed/PreparsedDocumentEntryTest.groovy
@@ -0,0 +1,62 @@
+package graphql.execution.preparsed
+
+import graphql.GraphQLError
+import graphql.InvalidSyntaxError
+import graphql.language.Document
+import graphql.language.SourceLocation
+import graphql.validation.ValidationError
+import graphql.validation.ValidationErrorType
+import spock.lang.Specification
+
+class PreparsedDocumentEntryTest extends Specification {
+    def "Ensure a non-null document returns"() {
+        given:
+        def document = new Document()
+
+        when:
+        def docEntry = new PreparsedDocumentEntry(document)
+
+        then:
+        docEntry.document == document
+        docEntry.errors == null
+    }
+
+    def "Ensure a null document throws NPE"() {
+        when:
+        new PreparsedDocumentEntry((Document) null)
+
+        then:
+        thrown(NullPointerException)
+    }
+
+    def "Ensure a non-null errors returns"() {
+        given:
+        def errors = [new InvalidSyntaxError(new SourceLocation(0, 0)),
+                      new ValidationError(ValidationErrorType.InvalidSyntax)]
+
+        when:
+        def docEntry = new PreparsedDocumentEntry(errors)
+
+        then:
+        docEntry.document == null
+        docEntry.errors == errors
+    }
+
+    def "Ensure a null errors throws NPE"() {
+        when:
+        new PreparsedDocumentEntry((List<GraphQLError>) null)
+
+        then:
+        thrown(NullPointerException)
+    }
+
+    def "Ensure a null error throws NPE"() {
+        when:
+        new PreparsedDocumentEntry((GraphQLError) null)
+
+        then:
+        thrown(NullPointerException)
+    }
+
+
+}
